Global warming may not reduce the number of weather-related deaths, according to a new study.
Some observers claim milder winters will result in fewer deaths from freezing and automobile accidents. A U.N. draft report scheduled for publication in March states some positive effects of global climate change. These include shifts in food production, reduction of some diseases, and fewer deaths due to extreme cold.
In this new study, however, researchers believe unknown weather patterns, and an increase in the severity of storms, could kill as many people as cold winters.
Public health records covering 60 years were examined by scientists from the University College London and the University of Exeter. Causes of wintertime deaths were compiled into three blocks of 20 years each. The investigation was focused on the United Kingdom, where records were collected.
From 1951 to 1971, cold weather was the cause of many winter deaths, the study noted. During the 20 years between 1971 and 1991, both cold and influenza were each named as leading causes of death. In the next two decades, from 1991 to 2011, the flu was responsible for the greatest number of fatalities.
"We've shown that the number of cold days in a winter no longer explains its number of excess deaths. Instead, the main cause of year to year variation in winter mortality in recent decades has been flu," Philip Straddon of the University of Exeter Medical School said.
Despite one of the coldest winters in decades over much of the United States, England and other nations of the UK have experienced a warmer-than-normal winter season this year. The study states several reasons winter deaths would be reduced, even without more moderate temperatures.
"Over the past few decades... the UK and other temperate countries have simultaneously experienced better housing, improved health care, higher incomes and greater awareness of the risks of cold. The link between winter temperatures and [excess winter deaths] may therefore no longer be as strong as before," researchers wrote in the study.
In order to calculate excess winter deaths (EWD), study leaders take the number of deaths occurring from December to March, and subtract the average number of deaths which happen during August to November of the previous year and the following April to July. The number of EWD's in the United Kingdom is usually between 25,000 and 31,000 people.
Philip Straddon and his team believe their research should have implications on public policy. They state efforts to prevent wintertime deaths and to lower the incidence of influenza should be maintained.
Details of the study were published in the journal Nature Climate Change.
